Burner and furnace arrangements, particularly double burner arrangements



July 26, 1966 A. SCHNEIDER BURNER AND FURNACE ARRANGEMENTS, PARTICULARLY DOUBLE BURNER ARRANGEMENTS Filed July 27, 1964 FIG-l 2 Sheets-Sheet l VERT|CAL,HORIZONTAL,OR

SPIRAL LIQUID OR VAPOR T TUBES INSULATION INVENTOR. AUGUST SCHNEIDER ATTORNEYS J ly 1966 A. SCHNEIDER 3,262,430

BURNER AND FURNACE ARRANGEMENTS, PARTICULARLY DOUBLE BURNER ARRANGEMENTS Filed July 27, 1964 2 Sheets-Sheet 2 INVENTOR,

AUGUST SCHNEIDER BY m; 7.14%

ATTORNEYS United States Patent 3,262,430 BURNER AND FURNACE ARRANGEMENTS, PAR- TICULARLY DOUBLE BURNER ARRANGE- MENTS August Schneider, Marl, Germany, assignor to Chemische Werke ll-Iuls Aktiengesellschaft, Marl, Germany Filed July 27, 1964, Ser. No. 385,425 Claims priority, application Germany, Aug. 9, 1963, C 30,657 9 Claims. (Cl. 122-235) This invention relates to burner and furnace arrangements, and particularly to double burner arrangements having particular benefits with regard to size and operational characteristics.

It is known to provide double or multiple burners which essentially represent duplication of single chambers and also to provide step-wise subdivision of burners in a chamber.

It is further known, particularly in connection with vertical cyclone-like firing arrangements, to locate several burners adjacent one another or above one another, and also to provide an annular series of burners.

Except for the annular burner arrangement for single chambers, any arrangement of burners adjacent one another has the disadvantage that the fuel inlet is eccentrically located and hence the natural advantages of vertical cyclone-like firing are lost.

The previously known arrangements employing superimposed firing chambers have the disadvantage that the individual chambers are joined in some manner and thus they could not be operated entirely independently as might be necessary under a condition of partial load.

The present invention relates to a solution of the difficulties referred to above and, more specifically, to a double furnace having vertical cyclone-like firing chambers spaced one above the other and arranged co-axially with respect to a single center flue. These chambers are also sufli ciently independent as to permit independent operation thereof but so integrated as to permit efficient combined operation.

The present invention is realized, in brief, by providing an upper chamber having a center flue cylinder and therebelow a lower chamber having its own center flue cylinder which extends upwardly into the lower end of the flue cylinder of the upper chamber.

With an arrangement of this nature, the gaseous currents will always enter the flue located at the center of the arrangement, and because of this, the chambers can be kept within certain maximum dimensional limits, even when designed for high capacity.

The arrangement of the present invention has the advantage that when the furnace charge is small, one only of the two chambers needs to be operated. It is preferable for the upper chamber to be larger and have a greater capacity so that it will be capable of producing about 60% of the total yield. The upper chamber can furthermore be advantageously designed for ring-step firing, and this will enable the upper chamber to conform better to partial load requirements, even down to 20% of the total yield with liquid slag withdrawn.

With respect to these independently operable chambers, they can be operated separately with partial loads and may be supplied by separate mills, and it is also possible for the two chambers to be fired with respectively different fuels and likewise for the chambers themselves to have respectively different designs.

FIGURE 1 is an axial section taken through the burner chambers of the invention and showing the interrelation of the two furnace sections.

FIGURE 2 is an axial section taken through the burner 3,262,430 Patented July 26, 1966 chambers of the invention, illustrating the arrangement of the burners in the upper chamber.

FIGURE 3 is an enlarged partial sectional view taken on line 33 of FIGURE 1 and depicting the construction of the walls and position of lines embedded therein.

The nature of the present invention will be more clearly understood by reference to the accompanying drawings which show two co-axial vertically separated cyclone-like melting chambers a and e. Into the burning space of the lower chamber a fuel and air are introduced through lateral openings generally designated at a which can take the form of any conventional burner nozzle structure and which can be arranged about the chamber according to any desired distribution pattern.

The gaseous products of combustion pass from chamber a through a grate b and enter the centrally arranged flue section d for the lower chamber which extends upwardly through the top wall portion a" of chamber a.

Slag formed in chamber a passes downwardly through a central outlet 0 which could, of course, be peripherally located on the bottom of chamber a if desired, as is the corresponding slag outlet opening g in the upper chamber.

As to the upper chamber 2, this is substantially larger than chamber a and the bottom wall of chamber e consists at least in part of the aforementioned top wall a" of chamber a.

Fuel and air can be introduced into upper chamber e from above or from the side as diagrammatically illustrated at e. The specific arrangement and distribution of the burners is subject to substantial variation according to practices known in the art.

The gaseous products of combustion from chamber e pass through grate 7 located in the bottom of flue section It for the upper chamber and then pass upwardly together with any gases introduced into flue section it from flue section d.

Grate f is positioned laterally and fits between the entrance end of flue section h and the exit end of fiue section d. Both grates d and foam be positioned vertically or inclined and they can be in the direction of the flow of the gases or in suitable intermediate positions as may be desired.

Upper chamber 2 has one or more slag outlets g which are separate from the lower chamber a.

It will be appreciated that flue sections d and h are in telescope with each other so that gases coming out the upper end of flue section d will have no tendency to enter upper chamber e and similarly, no gases will pass from chamber e into flue section d.

Furthermore, a minimum of radiant heat will be able to pass from one chamber to the other because the chambers are substantially completely isolated. No hot gases from either of the chambers can enter the other, and thus under partial load conditions, when one chamber is not operating it will remain cool even to the extent that no circulation of cooling air is required. Furthermore, the substantially complete isolation of the two chambers from each other in this manner makes it possible for repairs to be made to one chamber, as to the burners or the like thereof, while the other chamber is operating.

FIGURE 3 shows on the left side an enlarged section of the outer wall ofthe upper burner chamber e, while on the right, the gas-impermeable wall of the radiation chamber h (flue) is shown. The annular chamber in which the mixture of fuel and air is burning is formed between these walls. The boiler pipes 2 cannot withstand the high combustion temperatures in the furnace, and they are therefore protected by a fireproof refractory 3. The boiler pipes 2 can extend vertically, horizontally, or spirally. Heat losses from the furnace are minimized by the application of an insulating coating 1 on the outside of the furnace. Boiler pipes 2 are provided in the gasimpermeable wall separating burner chamber 2 from the radiation chamber 11. These pipes are positioned in the wall nearer the chamber 11 than chamber e, and in some instances it is even desirable to leave a portion of the pipes exposed to improve heat transfer between the burner gases and the fluid flowing through lines 2.

' The walls of the lower chamber are similarly constructed.

The combination of chambers as disclosed is nevertheless quite compact. The particular co-axial telescopic arrangement of the flue sections and the arrangement of the chambers a and e is such that it is possible to regulate the temperature profile of the gases of combustion in the flue, when the gases from the respective chambers are at different temperatures and in different proportions. Efficiency of operation is thus possible by regulation of the particular design of the chambers and flue sections which has not heretofore been possible in furnace arrangements of the nature disclosed.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions; and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What is claimed is:

1. A furnace having chambers capable of operating independently, comprising: wall means defining an upper chamber and separate wall means defining a lower chamber, said chambers being coaxial, the wall means constituting the lower portion of the upper chamber and the wall means constituting the upper portion of the lower chamber being substantially separated to reduce heat transfer therebetween, wall means defining central flues in both the upper and lower chambers which are open only at their upper and lower ends, the upper end of the lower flue extending into the lower end of the upper flue and being radially spaced therefrom, and burner means in both chambers for supplying combustible fuel means thereto.

2. The furnace of claim 1 wherein the burner means in the upper chamber comprises a plurality of burners located at different levels of the chamber to form a stepped burner arrangement.

3. The furnace of claim 1 wherein the chambers are isolated from each other, except for the extension of the lower flue into the upper flue in the upper chamber, thereby to permit independently different types of operation in the chambers.

4. The furnace of claim 1, further characterized by a first means defining a slag outlet in the upper chamber, and a second means defining a separate slag outlet in the lower chamber.

5. The furnace of claim 1, further characterized by first grate means covering open portions of the lower end of the fiue in the lower chamber, and second grate means covering open annular portions of the lower end of the flue in the upper chamber, said second grate means surrounding the upper end of the flue extending from the lower chamber.

6. The furnace defined by claim 4 wherein the first means defining a slag outlet is peripherally spaced in the lower portion of the upper chamber and the second means defining a separate slag outlet is axially spaced in the lower chamber.

7. The furnace of claim 1 wherein tubes for carrying fluid are embedded in the wall means defining the chambers.

8. The furnace of claim 1 wherein tubes for carrying fluid are embedded in said wall means defining the central flues.

9. The furnace of claim 1 wherein both wall means defining the central fiues are gas-impermeable.

References Cited by the Examiner UNITED STATES PATENTS 3,188,987 6/1965 Anschutz -22 FOREIGN PATENTS 536,697 4/1955 Belgium.

OTHER REFERENCES German application No. 1,070,330, December 3, 1959. German application No. 1,148,688, May 16, 1963.

CHARLES J. MYHRE, Primary Examiner. 

1. A FURNACE HAVING CHAMBERS CAPABLE OF OPERATING INDEPENDENTLY, COMPRISING: WALL MEANS DEFINING AN UPPER CHAMBER AND SEPARATE WALL MEANS DEFINING A LOWER CHAMBER, SAID CHAMBERS BEING COAXIAL, THE WALL MEANS CONSTITUTING THE LOWER PORTION OF THE UPPER CHAMBER AND THE WALL MEANS CONSTITUTING THE UPPER PORTION OF THE LOWER CHAMBER BEING SUBSTANTIALLY SEPARATED TO REDUCE HEAT TRANSFER THEREBETWEEN, WALL MEANS DEFINING CENTRAL FLUES IN BOTH THE UPPER AND LOWER CHAMBERS WHICH ARE OPEN ONLY AT THEIR UPPER AND LOWER ENDS, THE UPPER END OF THE LOWER FLUE EXTENDING INTO THE LOWER END OF THE UPPER FLUE AND BEING RADIALLY SPACED THEREFROM, AND BURNER MEANS IN BOTH CHAMBERS FOR SUPPLYING COMBUSTIBLE FUEL MEANS THERETO. 